Cisco syslog configure

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1. Cisco syslog：
    cisco2901#configure terminal                                                                 
    cisco2901(config)#logging host 10.1.1.1                                                 <----------設定收 syslog 的主機 IP
    cisco2901(config)#logging on                                                                  <----------啟動 syslog
  備註：
    cisco2901(config)#logging trap (0-7)                                <----------設定 syslog 等級(預設等級為3)
            <0-7> Logging severity level
            alerts Immediate action needed                    (severity=1)
            critical Critical conditions                             (severity=2)
            debugging Debugging messages                    (severity=7)
            emergencies System is unusable                   (severity=0)
            errors Error conditions                                  (severity=3)
            informational Informational messages          (severity=6)
            notifications Normal but significant condit   (severity=5)
            warnings Warning conditions                        (severity=4)